Protestant countries are basically just Anglos and Northern Europe. All imperial core and subject to the issues with revolutionary potential described by Marx, Engels et al. In addition, many foci of revolution have been national liberation struggles, particularly in colonies, and the protestant colonizers did not prioritize proselytization, missionaries, or integration in their colonial projects. They enforced white supremacy and did settler colonial genocides instead. So colonies of protestant colonizers did have successful revolutions, including proletarian ones, but they were often not protestant, instead reflecting more their immediate historical demographics.